Experimental materials:
Sodium alginate, calcium lactate, measuring cup, pigment, hemispherical mold, stirring rod, hot water and clear water.
Experimental steps:
1. Pour about 10g of sodium alginate into a measuring cup, add 240ml of hot water, drop the pigment, stir 10min, let it stand for 5min, then continue stirring for 5min, add the pigment and let it stand for about an hour to obtain a thick sodium alginate solution.
2. Pour about 450ml of clean water into a measuring cup, add 25g of calcium lactate, and stir with a stirring rod until there are no particles to obtain a clear calcium lactate solution.
3. Soak the hemispherical mold in calcium lactate solution, slowly pour a little sodium alginate solution into the mold, then slowly immerse the mold in calcium lactate solution, gently shake the mold, and then turn the grinding tool over. Water sprite balls will be separated from the mold, and water sprite with different colors can be made.
4. water sprite can be taken out and put into clean water after soaking in calcium lactate solution for 5 minutes. The longer the soaking time, the better the elasticity.
Experimental principle:
There is a substance called "sodium alginate" in the experimental materials. When water is heated, it will quickly form a gel, and then it will be soaked in water with calcium lactate. Calcium ions in the calcium lactate solution will exchange ions rapidly, thus forming a gel film on the surface, and slowly "water sprite" will solidify.
The real face of the water baby sold outside is a kind of water-absorbing resin, which is usually made of starch mixed with acrylonitrile or acrylate. Both acrylonitrile and acrylate have certain toxicity. Moreover, it is impossible for merchants to use expensive food pigments in their production, and some industrial pigments may be added. Therefore, children are advised not to play with such things. If you come into contact with their skin, you should wash it quickly, and don't let the children eat it by mistake, otherwise the consequences will be unimaginable, and parents should attach great importance to it.